Abstract
Intracellular membrane traffic is thought to be regulated in part by SNAREs, integral membrane proteins on transport vesicles (v-SNAREs) and target organelles (t-SNAREs) that bind to each other and mediate bilayer fusion. All known SNARE-mediated fusion events involve a member of the syntaxin family of t-SNAREs. Sequence comparisons identify eight such proteins encoded in the yeast genome, of which six have been characterized. We describe here the remaining two, Tlg1p and Tlg2p. These have the expected biochemical properties of t-SNAREs, and are located in separable compartments which correspond to a putative early endosome and the yeast equivalent of the TGN, respectively. They co-precipitate with the v-SNARE Vti1p, which is implicated in Golgi-endosome traffic and, remarkably, binds to five different syntaxins. Tlg1p also binds the plasma membrane v-SNARE Snc1p. Both Tlg1p and Tlg2p are required for efficient endocytosis and to maintain normal levels of TGN proteins. However, neither is required for intra-Golgi traffic. Since no further syntaxins have been identified in yeast, this implies that the Golgi apparatus can function with a single syntaxin, Sed5p.
Full Text
The Full Text of this article is available as a PDF (811.2 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Aalto M. K., Ronne H., Keränen S. Yeast syntaxins Sso1p and Sso2p belong to a family of related membrane proteins that function in vesicular transport. EMBO J. 1993 Nov;12(11):4095–4104. doi: 10.1002/j.1460-2075.1993.tb06093.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Banfield D. K., Lewis M. J., Pelham H. R. A SNARE-like protein required for traffic through the Golgi complex. Nature. 1995 Jun 29;375(6534):806–809. doi: 10.1038/375806a0. [DOI] [PubMed] [Google Scholar]
- Bannykh S. I., Balch W. E. Membrane dynamics at the endoplasmic reticulum-Golgi interface. J Cell Biol. 1997 Jul 14;138(1):1–4. doi: 10.1083/jcb.138.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Becherer K. A., Rieder S. E., Emr S. D., Jones E. W. Novel syntaxin homologue, Pep12p, required for the sorting of lumenal hydrolases to the lysosome-like vacuole in yeast. Mol Biol Cell. 1996 Apr;7(4):579–594. doi: 10.1091/mbc.7.4.579. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bennett M. K. SNAREs and the specificity of transport vesicle targeting. Curr Opin Cell Biol. 1995 Aug;7(4):581–586. doi: 10.1016/0955-0674(95)80016-6. [DOI] [PubMed] [Google Scholar]
- Bock J. B., Klumperman J., Davanger S., Scheller R. H. Syntaxin 6 functions in trans-Golgi network vesicle trafficking. Mol Biol Cell. 1997 Jul;8(7):1261–1271. doi: 10.1091/mbc.8.7.1261. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bryant N. J., Stevens T. H. Two separate signals act independently to localize a yeast late Golgi membrane protein through a combination of retrieval and retention. J Cell Biol. 1997 Jan 27;136(2):287–297. doi: 10.1083/jcb.136.2.287. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cooper A. A., Stevens T. H. Vps10p cycles between the late-Golgi and prevacuolar compartments in its function as the sorting receptor for multiple yeast vacuolar hydrolases. J Cell Biol. 1996 May;133(3):529–541. doi: 10.1083/jcb.133.3.529. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cowles C. R., Snyder W. B., Burd C. G., Emr S. D. Novel Golgi to vacuole delivery pathway in yeast: identification of a sorting determinant and required transport component. EMBO J. 1997 May 15;16(10):2769–2782. doi: 10.1093/emboj/16.10.2769. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cunningham K. W., Wickner W. T. Yeast KEX2 protease and mannosyltransferase I are localized to distinct compartments of the secretory pathway. Yeast. 1989 Jan-Feb;5(1):25–33. doi: 10.1002/yea.320050105. [DOI] [PubMed] [Google Scholar]
- Elble R. A simple and efficient procedure for transformation of yeasts. Biotechniques. 1992 Jul;13(1):18–20. [PubMed] [Google Scholar]
- Farquhar M. G. Progress in unraveling pathways of Golgi traffic. Annu Rev Cell Biol. 1985;1:447–488. doi: 10.1146/annurev.cb.01.110185.002311. [DOI] [PubMed] [Google Scholar]
- Franzusoff A., Redding K., Crosby J., Fuller R. S., Schekman R. Localization of components involved in protein transport and processing through the yeast Golgi apparatus. J Cell Biol. 1991 Jan;112(1):27–37. doi: 10.1083/jcb.112.1.27. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Graham T. R., Emr S. D. Compartmental organization of Golgi-specific protein modification and vacuolar protein sorting events defined in a yeast sec18 (NSF) mutant. J Cell Biol. 1991 Jul;114(2):207–218. doi: 10.1083/jcb.114.2.207. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gruenberg J., Maxfield F. R. Membrane transport in the endocytic pathway. Curr Opin Cell Biol. 1995 Aug;7(4):552–563. doi: 10.1016/0955-0674(95)80013-1. [DOI] [PubMed] [Google Scholar]
- Hardwick K. G., Pelham H. R. SED5 encodes a 39-kD integral membrane protein required for vesicular transport between the ER and the Golgi complex. J Cell Biol. 1992 Nov;119(3):513–521. doi: 10.1083/jcb.119.3.513. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harris S. L., Waters M. G. Localization of a yeast early Golgi mannosyltransferase, Och1p, involves retrograde transport. J Cell Biol. 1996 Mar;132(6):985–998. doi: 10.1083/jcb.132.6.985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hay J. C., Chao D. S., Kuo C. S., Scheller R. H. Protein interactions regulating vesicle transport between the endoplasmic reticulum and Golgi apparatus in mammalian cells. Cell. 1997 Apr 4;89(1):149–158. doi: 10.1016/s0092-8674(00)80191-9. [DOI] [PubMed] [Google Scholar]
- Hicke L., Riezman H. Ubiquitination of a yeast plasma membrane receptor signals its ligand-stimulated endocytosis. Cell. 1996 Jan 26;84(2):277–287. doi: 10.1016/s0092-8674(00)80982-4. [DOI] [PubMed] [Google Scholar]
- Hicke L., Zanolari B., Pypaert M., Rohrer J., Riezman H. Transport through the yeast endocytic pathway occurs through morphologically distinct compartments and requires an active secretory pathway and Sec18p/N-ethylmaleimide-sensitive fusion protein. Mol Biol Cell. 1997 Jan;8(1):13–31. doi: 10.1091/mbc.8.1.13. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kaiser C. A., Schekman R. Distinct sets of SEC genes govern transport vesicle formation and fusion early in the secretory pathway. Cell. 1990 May 18;61(4):723–733. doi: 10.1016/0092-8674(90)90483-u. [DOI] [PubMed] [Google Scholar]
- Lewis M. J., Pelham H. R. SNARE-mediated retrograde traffic from the Golgi complex to the endoplasmic reticulum. Cell. 1996 Apr 19;85(2):205–215. doi: 10.1016/s0092-8674(00)81097-1. [DOI] [PubMed] [Google Scholar]
- Lewis M. J., Rayner J. C., Pelham H. R. A novel SNARE complex implicated in vesicle fusion with the endoplasmic reticulum. EMBO J. 1997 Jun 2;16(11):3017–3024. doi: 10.1093/emboj/16.11.3017. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Luo W. j., Chang A. Novel genes involved in endosomal traffic in yeast revealed by suppression of a targeting-defective plasma membrane ATPase mutant. J Cell Biol. 1997 Aug 25;138(4):731–746. doi: 10.1083/jcb.138.4.731. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mironov A. A., Weidman P., Luini A. Variations on the intracellular transport theme: maturing cisternae and trafficking tubules. J Cell Biol. 1997 Aug 11;138(3):481–484. doi: 10.1083/jcb.138.3.481. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nagahama M., Orci L., Ravazzola M., Amherdt M., Lacomis L., Tempst P., Rothman J. E., Söllner T. H. A v-SNARE implicated in intra-Golgi transport. J Cell Biol. 1996 May;133(3):507–516. doi: 10.1083/jcb.133.3.507. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nichols B. J., Ungermann C., Pelham H. R., Wickner W. T., Haas A. Homotypic vacuolar fusion mediated by t- and v-SNAREs. Nature. 1997 May 8;387(6629):199–202. doi: 10.1038/387199a0. [DOI] [PubMed] [Google Scholar]
- Nothwehr S. F., Roberts C. J., Stevens T. H. Membrane protein retention in the yeast Golgi apparatus: dipeptidyl aminopeptidase A is retained by a cytoplasmic signal containing aromatic residues. J Cell Biol. 1993 Jun;121(6):1197–1209. doi: 10.1083/jcb.121.6.1197. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pelham H. R. Getting through the Golgi complex. Trends Cell Biol. 1998 Jan;8(1):45–49. doi: 10.1016/s0962-8924(97)01185-9. [DOI] [PubMed] [Google Scholar]
- Pelham H. R., Hardwick K. G., Lewis M. J. Sorting of soluble ER proteins in yeast. EMBO J. 1988 Jun;7(6):1757–1762. doi: 10.1002/j.1460-2075.1988.tb03005.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Piper R. C., Bryant N. J., Stevens T. H. The membrane protein alkaline phosphatase is delivered to the vacuole by a route that is distinct from the VPS-dependent pathway. J Cell Biol. 1997 Aug 11;138(3):531–545. doi: 10.1083/jcb.138.3.531. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Protopopov V., Govindan B., Novick P., Gerst J. E. Homologs of the synaptobrevin/VAMP family of synaptic vesicle proteins function on the late secretory pathway in S. cerevisiae. Cell. 1993 Sep 10;74(5):855–861. doi: 10.1016/0092-8674(93)90465-3. [DOI] [PubMed] [Google Scholar]
- Redding K., Holcomb C., Fuller R. S. Immunolocalization of Kex2 protease identifies a putative late Golgi compartment in the yeast Saccharomyces cerevisiae. J Cell Biol. 1991 May;113(3):527–538. doi: 10.1083/jcb.113.3.527. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rothman J. E. Mechanisms of intracellular protein transport. Nature. 1994 Nov 3;372(6501):55–63. doi: 10.1038/372055a0. [DOI] [PubMed] [Google Scholar]
- Rothman J. E., Warren G. Implications of the SNARE hypothesis for intracellular membrane topology and dynamics. Curr Biol. 1994 Mar 1;4(3):220–233. doi: 10.1016/s0960-9822(00)00051-8. [DOI] [PubMed] [Google Scholar]
- Rothman J. E., Wieland F. T. Protein sorting by transport vesicles. Science. 1996 Apr 12;272(5259):227–234. doi: 10.1126/science.272.5259.227. [DOI] [PubMed] [Google Scholar]
- Sauer B. Functional expression of the cre-lox site-specific recombination system in the yeast Saccharomyces cerevisiae. Mol Cell Biol. 1987 Jun;7(6):2087–2096. doi: 10.1128/mcb.7.6.2087. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schandel K. A., Jenness D. D. Direct evidence for ligand-induced internalization of the yeast alpha-factor pheromone receptor. Mol Cell Biol. 1994 Nov;14(11):7245–7255. doi: 10.1128/mcb.14.11.7245. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schekman R., Mellman I. Does COPI go both ways? Cell. 1997 Jul 25;90(2):197–200. doi: 10.1016/s0092-8674(00)80326-8. [DOI] [PubMed] [Google Scholar]
- Semenza J. C., Hardwick K. G., Dean N., Pelham H. R. ERD2, a yeast gene required for the receptor-mediated retrieval of luminal ER proteins from the secretory pathway. Cell. 1990 Jun 29;61(7):1349–1357. doi: 10.1016/0092-8674(90)90698-e. [DOI] [PubMed] [Google Scholar]
- Sikorski R. S., Hieter P. A system of shuttle vectors and yeast host strains designed for efficient manipulation of DNA in Saccharomyces cerevisiae. Genetics. 1989 May;122(1):19–27. doi: 10.1093/genetics/122.1.19. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stack J. H., Horazdovsky B., Emr S. D. Receptor-mediated protein sorting to the vacuole in yeast: roles for a protein kinase, a lipid kinase and GTP-binding proteins. Annu Rev Cell Dev Biol. 1995;11:1–33. doi: 10.1146/annurev.cb.11.110195.000245. [DOI] [PubMed] [Google Scholar]
- Söllner T., Bennett M. K., Whiteheart S. W., Scheller R. H., Rothman J. E. A protein assembly-disassembly pathway in vitro that may correspond to sequential steps of synaptic vesicle docking, activation, and fusion. Cell. 1993 Nov 5;75(3):409–418. doi: 10.1016/0092-8674(93)90376-2. [DOI] [PubMed] [Google Scholar]
- Söllner T., Whiteheart S. W., Brunner M., Erdjument-Bromage H., Geromanos S., Tempst P., Rothman J. E. SNAP receptors implicated in vesicle targeting and fusion. Nature. 1993 Mar 25;362(6418):318–324. doi: 10.1038/362318a0. [DOI] [PubMed] [Google Scholar]
- Søgaard M., Tani K., Ye R. R., Geromanos S., Tempst P., Kirchhausen T., Rothman J. E., Söllner T. A rab protein is required for the assembly of SNARE complexes in the docking of transport vesicles. Cell. 1994 Sep 23;78(6):937–948. doi: 10.1016/0092-8674(94)90270-4. [DOI] [PubMed] [Google Scholar]
- Vida T. A., Emr S. D. A new vital stain for visualizing vacuolar membrane dynamics and endocytosis in yeast. J Cell Biol. 1995 Mar;128(5):779–792. doi: 10.1083/jcb.128.5.779. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wada Y., Nakamura N., Ohsumi Y., Hirata A. Vam3p, a new member of syntaxin related protein, is required for vacuolar assembly in the yeast Saccharomyces cerevisiae. J Cell Sci. 1997 Jun;110(Pt 11):1299–1306. doi: 10.1242/jcs.110.11.1299. [DOI] [PubMed] [Google Scholar]
- Walch-Solimena C., Blasi J., Edelmann L., Chapman E. R., von Mollard G. F., Jahn R. The t-SNAREs syntaxin 1 and SNAP-25 are present on organelles that participate in synaptic vesicle recycling. J Cell Biol. 1995 Feb;128(4):637–645. doi: 10.1083/jcb.128.4.637. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Weimbs T., Low S. H., Chapin S. J., Mostov K. E., Bucher P., Hofmann K. A conserved domain is present in different families of vesicular fusion proteins: a new superfamily. Proc Natl Acad Sci U S A. 1997 Apr 1;94(7):3046–3051. doi: 10.1073/pnas.94.7.3046. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wilcox C. A., Redding K., Wright R., Fuller R. S. Mutation of a tyrosine localization signal in the cytosolic tail of yeast Kex2 protease disrupts Golgi retention and results in default transport to the vacuole. Mol Biol Cell. 1992 Dec;3(12):1353–1371. doi: 10.1091/mbc.3.12.1353. [DOI] [PMC free article] [PubMed] [Google Scholar]
- von Mollard G. F., Nothwehr S. F., Stevens T. H. The yeast v-SNARE Vti1p mediates two vesicle transport pathways through interactions with the t-SNAREs Sed5p and Pep12p. J Cell Biol. 1997 Jun 30;137(7):1511–1524. doi: 10.1083/jcb.137.7.1511. [DOI] [PMC free article] [PubMed] [Google Scholar]